A simple reduction-oxidation route to prepare Co3O4 nanocrystals

Cobalt oxide (Co3O4) nanoparticles have been successfully prepared via a si mple reduction-oxidation route at room temperature and normal pressure, usi ng cobalt chloride as the reactant and sodium acetate as the basic agent. O wing to employing a gamma -irradiation technique, no extra reducing reagent was introduced into the system. The experiment contained two steps: first, cobalt (II) ions were reduced to cobalt atoms by gamma -irradiation in nit rogen. Then, cobalt atoms were oxidized to cobalt oxide (Co3O4) in air. The TEM images showed that cobalt oxide powders consisted of crystallized sphe rical particles and amorphous wire-like particles. (C) 2001 Elsevier Scienc e Ltd. All rights reserved.